Improvements in computing technologies have changed the way people accomplish various tasks. For example, the Internet, and more specifically electronic mail (email), allows users to exchange documents, pictures, files and the like relatively quickly. Blacklisting has been used to prevent unwanted messages, commonly referred to as “spam”, from reaching a legitimate receiver. In fact, estimates suggest that well over ninety percent (90%) of all incoming traffic to a mail platform is spam. This spam needs to be discarded to ensure that a recipient's inbox is not bombarded with unsolicited, unwanted, and often fraudulent emails. A goal of a spam filter is to reduce the flow of unsolicited mail to the recipient's inbox. In this manner, a user (or organization, or any other entity) can specify one or more contacts that the user does not want to receive messages from, thereby blacklisting the one or more contacts. Estimates suggest that blacklists are effective in stopping seventy to eighty percent (70-80%) of spam.
Many spam filters block emails based on the sender's Internet Protocol (IP) address. Spammers can try to evade such filters by periodically changing their own IP address, but the available address space under the current IP scheme (Version 4, or IPv4) is limited, and spammers cannot always find a new address to use. However, the Internet Engineering Task Force (IETF) designated Internet Protocol, Version 6 (IPv6) as the successor to IPv4. Addresses in IPv6 are one-hundred twenty eight (128) bits, compared to the mere thirty-two (32) bits in IPv4. IPv6 space will be so vast that a spammer will have many more source addresses from which to send their spam, making filtering even more difficult than it is today. Accordingly, the blacklisting techniques that have been utilized in conjunction with IPv4 will be less in terms of filtering spam messages under IPv6.
Additionally, as the number of Internet users continues to increase, the burden placed on filtering and processing algorithms increases as well. Stated in a slightly different way, traditional inbound message processing techniques will be ineffective from a performance standpoint in the not too distant future.